Interface of the Docker extension is not available in Plesk: Local Docker node is missing

Symptoms

• The Docker extension isn't available. The following message is displayed instead:
  

  PLESK_WARN: Warning:Local Docker node is missing. Refer to this KB article to resolve this issue.
  The ability to work with remote nodes is available only in the paid version of the extension. You can buy the extension here.

• Local docker service itself is up & running:

  # systemctl status docker
  * docker.service - Docker Application Container Engine
  Loaded: loaded (/usr/lib/systemd/system/docker.service; enabled; vendor preset: disabled)
  Active: active (running) since Sat 2023-02-04 09:11:40 CET; 2 days ago

Cause

The Configurations table of the docker database(/usr/local/psa/var/modules/docker/db.sqlite3) is empty:

# sqlite> select * from Configurations;
sqlite> 

Resolution

1. Connect to the server via SSH
2. Open the Docker sqlite db:
   

   # sqlite3 /usr/local/psa/var/modules/docker/db.sqlite3

3. Insert the configuration string for a local service:
   

   # insert into Configurations (id,active,remote,ssl) values (1,1,"",1);